How do I start a background process from the OS/2 Warp command line?
Look up the START and DETACH commands in the online Command Reference.
If you wish to start a DOS session with nondefault settings, use a utility such as STARTD. If you wish to start an OS/2 Warp session from a DOS session, try OS2EXEC. Both (and several others) are available from (3.2) Shareware and Freeware Sources.
(3.2) Shareware and Freeware Sources